THE 4 STAGES OF M!+0$!$

Prophase

Telophase

Metaphase

Anaphase

START

Prophase

The chromosomes coil. The nuclear membrane disintegrates.

The spindle apparatus forms. The nucleolus disappears.

Each centrosome  of an animal cell contains two centrioles. Plant cells do not have centrioles but they do form

spindle fibers. 

Photographs of Prophase

Plant (onion)

Animal cell (early prophase)

Metaphase

The nuclear membrane disappears completely. In animal cells, the two pair of centrioles align at

opposite poles of the cell. Polar fibers continue to extend from the poles to

the center of the cell. Chromosomes move randomly until they attach to

polar fibers from both sides of their centromeres. Chromosomes align at the metaphase plate at

right angles to the spindle poles. Chromosomes are held at the metaphase plate by

the equal forces of the polar fibers pushing on the centromeres of the chromosomes.

Photographs of Metaphase

Plant cell (onion)

Animal cell (whitefish)

Anaphase

The paired centromeres in each distinct chromosome begin to move apart.

Once the paired sister chromatids separate from one another, each is considered a "full" chromosome. They are

referred to as daughter chromosomes. Through the spindle apparatus, the daughter chromosomes

move to the poles at opposite ends of the cell. The daughter chromosomes migrate centromere first and

the kinetochore fibers become shorter as the chromosomes near a pole.

In preparation for telophase, the two cell poles also move further apart during the course of anaphase. At the end of anaphase, each pole contains a complete compilation of

chromosomes.

Photographs of Anaphase

Early Anaphase Plant Cell (onion)

Late Anaphase Plant Cell (onion)

Animal Anaphase

Telophase

The polar fibers continue to lengthen. Nuclei begin to form at opposite poles.

The nuclear envelopes of these nuclei are formed from remnant pieces of the parent cell's nuclear envelope and

from pieces of the endomembrane system. Nucleoli (plural form of nucleolus) also reappear.

Chromatin fibers of chromosomes uncoil. After these changes, telophase/mitosis is largely complete

and the genetic "contents" of one cell have been divided equally into two.

Photographs of Telophase

Early Telophase Plant Cell (onion)

Late Telophase Plant Cell (onion)

Telophase Animal Cell (whitefish)

Glossary Spindle Apparatus (spindle fibers)- A collection of microtubules

attached to a centromere during mitosis and meiosis that are responsible for the movement of the chromosomes to opposite poles.

Centrosome- A small region of cytoplasm adjacent to the nucleus that contains the centrioles and serves to organize microtubules.

Centromere- a region of a chromosome where it attaches to a spindle fiber during mitosis and meiosis

Centriole- One of two cylindrical cellular structures that are composed of nine triplet microtubules and form the asters during mitosis.

Polar fibers-microtubules that make up the spindle fibers Chromatids- Either of the two daughter strands of a replicated

chromosome that are joined by a single centromere and separate during cell division to become individual chromosomes.

Kinetochore- Either of two submicroscopic attachment points for chromosomal microtubules, present on each centromere during the process of cell division

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Works Cited http://student.ccbcmd.edu/~gkaiser/

biotutorials/dna/mitosis/acprophaseB.html

http://biology.about.com/od/mitosis/ss/mitosisstep_3.htm

http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/acmetaphase.html

http://iknow.net/cell_div_education.html\

http://www.cellsalive.com/mitosis.htm

http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/actelophase.html

http://www.biologycorner.com/resources/cell_cycle.jpg